The present invention relates to pyrimidofuroxans of the general formula I ##STR1## in which A denotes ##STR2## where in each case the nitrogen atom is bonded via the C-4 and the carbon atom via the C-3 of the furoxan ring and the R radicals are defined as indicated in Claim 1, processes for their preparation and their use for the control and prevention of disorders of the cardiovascular system, in particular for the control and prevention of angina pectoris, and for the treatment of erectile dysfunctions.